GB597143A - Improvements in writing instruments - Google Patents

Abstract

597,143. Fountain pens, FEHLING, H. R. Sept. 18, 1945, No. 24050. [Class 146 (iii)] In a ball-point pen, the reservoir 8 and ball-section 4 are slidably mounted in a casing for retraction and projection and pressure is automatically applied to the ink when the pen is projected and is automatically reduced or removed when the pen is retracted. The pen proper comprises a ballholding section 4, a capillary feed conduit 5, and a sac 18 secured at one end to the conduit 5 and at the other end is clamped between two members 10, 11. One or more orifices 5a in the conduit allow ink to pass from the sac to the conduit. A sleeve 9 surrounds the sac 8 and the parts 4, 5, 8, 9, 10, 11 can slide as a unit in an outer casing 2 so as to project the ball-point 3 or retract it within the end 1 of the casing. A spring 6 extends between a shoulder 1<1> on the part 1 and a slidable collar 7 bearing against the sac, and is compressed as the pen is projected so as to apply pressure to the sac. To operate the instrument, a button 17 having a pin-and-slot connection 15, 16a with the casing is provided and carries a resilient ring 14 with a projection 14a which snaps into an opening 12b in the casing when the pen is in writing position. A knob 12a is provided on the usual clip 12 to release the projection 14a and allow the spring 6 to return the parts to inoperative position. A spring washer 13 is inserted between the parts 11, 14 to facilitate entry of the projection 14a into the opening 12b. An additional spring situated between the shoulder 1<1> and a collar on the conduit 5 may be provided to retract the pen into the casing, in which case the function of the spring 6 is solely to apply pressure to the sac. In the projected position, the ball-section 4 makes contact with the interior of the casing end 1 and is capable of a.slight rocking movement, the length of the conduit 5 affording a degree of resilience. The strength of the spring 6 may be such that the pressure exerted on the ink in the retracted position does not exceed the capillary pressure in the ball gap. Specification 584,974 is referred to.